1. Field of the Invention
The present invention relates to a method for assessing life-affecting damage on a rotary member that is subjected to repeated loading during operation. The method includes measuring a number of operating parameters and calculating a temperature increase during each loading from the operating parameters. A total temperature in a part of the rotary member is calculated for each loading by summation of a basic temperature of the rotary member before the loading concerned, and the temperature increase, and the values for the total temperature are used as a measure of the damage.
The present invention relates to a method for assessing life-affecting damage on a rotary member that is subjected to repeated loading during operation. The method includes measuring a number of operating parameters and calculating a temperature increase during each loading from the operating parameters. A total temperature in a part of the rotary member is calculated for each loading by summation of a basic temperature of the rotary member before the loading concerned, and the temperature increase, and the values for the total temperature are used as a measure of the damage.
The invention can be applied in, for example, a means of transport, such as a vehicle, a craft or other transport-types of equipment such as rail-mounted transport means. Application may also be made in such land vehicles, such as vehicles having wheels or caterpillar tracks. The invention is in particular suitable for application in a construction machine, such as a wheel loader, excavating machine or a frame-steered or articulated vehicle, also referred to as a dumper. The area of application of the invention is nevertheless not limited to these applications, and it can also be applied in stationary arrangements.
2. Background Art
U.S. Pat. No. 5,723,779 describes a system for producing an indication of the remaining life of a friction clutch. It is assumed that the temperature of the clutch disk is a decisive parameter for its life. The temperature of the clutch disk is determined by summation of a temperature increase on activation of the clutch and the basic temperature of the clutch disk before activation of the clutch. These two values are therefore added, and a measure of the temperature of the clutch disk during activation is obtained. A large number of parameters are measured for the calculation: speed difference in the clutch, pressure of the oil supplied to the piston that brings about engagement of the clutch, and loading time. The temperature of the coolant of the clutch is also measured. This temperature is used as a measure of the basic temperature of the clutch disk before every brake application.
However, it has become apparent that it would be desirable to have a method for assessing consumed life, which provides a more accurate result compared with the system according to U.S. Pat. No. 5,723,779.
It may furthermore be mentioned that methods are available for accurate calculation of temperature distribution in a loaded rotary member, such as FEM (Finite Element Methods). However, such methods require great computer power and take a relatively long time, which makes them less suitable for certain applications, such as in high-frequency measurement, calculation and logging of data, and especially when the calculation is to be performed in a computer in a vehicle.